Chondromalacia Patella, or "Runner's Knee", occurs when repeated stress on the knee causes inflammation and a gradual softening on the cartilage under the kneecap (patella). The inflimation of the cartilage prevents the kneecap from gliding smoothly over the end of the thigh bone (femur) therefore causing pain and swelling of the knee. The underside of the kneecap should be smooth and move within the femoral groove (a groove on the thigh bone). If the kneecap is pulled sideways, it becomes rough like sandpaper and the symptoms appear.
Runner's Knee is typically associated with a pain that increases gradually over a period of time, often a year or longer, until it is severe enough that the athlete seeks medical attention. Symptoms usually occur beneath or on both sides of the kneecap. Pain may be intensified with activites such as a short run, squatting or jumping. Stiffness may occur simply from prolonged sitting or descending stairs.
Runner's Knee accounts for 25% of the overuse injuries treated in sports clinics. Teenage girls are most commonly affected, but any active person age 14 or over may experience this pain syndrome.
Causes of Injury
- Overpronation causes the lower leg to rotate inward due to the unstable pronated foot. The kneecap moves in an abnormal side to side motion instead of gliding within the normal track of the femoral groove on the thigh bone.
- Weak quadriceps may contribute to injury because the thigh muscles normally aid in proper tracking of the kneecap.
- Muscle imbalance.
- Direct or repeated trauma.
- An untreated ligament injury.
- Some athletes may experience pain in one knee if they continually run along the same side of the road. The tilt in the road accentuates the pronation of the foot thus resulting in the abnormal tracking of the knee.
- History of trauma.
Short Term Treatment
- Decrease activity and consider swimming. When recovering avoid any exercise that puts weight on a bent knee.
- Rest if the knee is painful or swollen.
- Ice treatment for 15 minutes twice daily after activity to reduce pain and inflammation.
- Aspirin or ibuprofen. Or consult your physician about more sophisticated and effective anti-inflammatory medication.
Long Term Treatment
- Physiotherapy including stretching and strengthening exercises for the quadriceps, hamstrings and calves.
- Orthotic devices to correct abnormal foot mechanics.
Once the causes are determined and the appropriate steps have been taken to treat the condition, Runner's Knee should not keep the athlete from activity.